Outboard mounting height 1985 Johnson 115 v4

[scottcab]

Re: Motor issues? timing or carb link? plus photos

Re: Motor issues? timing or carb link? plus photos

 

[dazk14]

Re: Motor issues? timing or carb link? plus photos

Re: Motor issues? timing or carb link? plus photos

In your 2nd video, I don't see where you trim that motor out with any significance. We want to see that boat start to porpoise excessively or blow out. It could result in significant Rpm and speed increases.

From idle did you go immediately to WOT. Not a biggie, but would be helpful to see the hole shot.

That's an older design prop. A modern designed prop should run rings around it.

The black is unburned fuel/oil - not uncommon. Obviously, there is some engine work to track down. Don't start playing with adjustments until you have a thorough understanding.

What do the plugs look like.

 

[scottcab]

Re: Motor issues? timing or carb link? plus photos

Re: Motor issues? timing or carb link? plus photos

Thanks for the quick response dazk,
The 2nd video I was trimmed to about one second of trim shy of blowout and ventilation. The boat doesn't porpoise though. I can hear the motor start to ventilate just above the trim in the video. I do understand that it is a good idea to trim down to assists in planning speed, but I had my 15y/o nephew driving the boat for the first time while I shot that video, so I didn't have him touch the trim. I was mainly trying to show the height of the anti-cav plate in the water. Also, unfortunately that is the hole shot. Straight to full throttle, but of course that is without trimming in. Trimming in helps a little bit with planning speed.
As far as the prop goes, I also tried a SST Stiletto 17 pitch prop with minimal change. But that was before I raised the motor up the last inch. I will put the SST back on for another test run now that I am getting my max rpm and speed just before ventilating. The cupping might give me a little more.
Thanks for the black fluid info.
Spark plugs are brand new.
Thanks Scott

 

[dazk14]

Re: Motor issues? timing or carb link? plus photos

Re: Motor issues? timing or carb link? plus photos

Since the plugs are new (perfect), inspect them now that you have time on it. Basic color and differences are what you are looking for. May as well post a detailed pic.

Since you cannot raise the motor more, you won't be able to get all the benefits of the newer designed prop...

However, you should be able to trim out significantly more for top speed(cupping design/rake), have better acceleration(progressive pitch) and the vent holes should improve your holeshot.

Unfortunately, the effective pitch for the 2 props may not coincide.

 

[bob johnson]

Re: Outboard mounting height 1985 Johnson 115 v4

SST on a 15" pitch is a waste of money, Alu will normally function just as well in that speed range. From 19" and up in pitch I would recommend SST. Would however still like to see some pics of the rig and bottom, you should normally be able to pull a 17" at around 5K on that size of boat.

I have a 115 ocean runner, and i was runninga factory 17 pitch prop on the boat....when i went to the SST 15 pitch prop, i gained 600 rpm and about 5 mph.

and the 17 pitch aluminum prop was in perfect shape....

so I think the drop in pitch had some effect and the material had some effect.....usually you slow down a little when you drop in pitch...you may gain the rpm, that you need to be in the sweet spot fo running the motor. I GAINED speed and a BUNCH of roms when i dropped down in pitch and changed to the SST prop!

bob

 

[wired247]

Re: Motor issues? timing or carb link? plus photos

Re: Motor issues? timing or carb link? plus photos

You are having engine problems. You know that. That engine should be bumping into the 5500 plus range especially with the 15 pitch prop. With the prop up where it should be you should be able to push a 17 pitch up until 5500-5700 with relative ease. You have one cylinder that may be firing intermittently or your float level is set too high and you are pushing gas into the emulsion tubs as its running. Sync the carbs first. Make sure the throttle plate are fully closed when at idle. Follow the factory carb setup . I know its a little cryptic but you need to have the plates closed at idle and the stops set right. It does look like your throttle plates are fully open. Look at the roll pin on the top carb where it contacts the carb base and make sure its just a hair away from touching. That is WOT.

 

[scottcab]

Re: Motor issues? timing or carb link? plus photos

Re: Motor issues? timing or carb link? plus photos


Should there be fuel coming out of where the arrows are?

 

[SparkieBoat]

Re: Motor issues? timing or carb link? plus photos

Re: Motor issues? timing or carb link? plus photos

how much fuel?? if it is much then your needle valves need cleaning/replacing or your float needs adjusting/replacing.

 

[boobie]

Re: Motor issues? timing or carb link? plus photos

Re: Motor issues? timing or carb link? plus photos

No. Your float level could be off or you have some crap underneath the needle & seat.

 

[wired247]

Re: Outboard mounting height 1985 Johnson 115 v4

Without the engine running you should be able to pump the bulb and have it stay firm AND the indicator on the back side of the fuel pump will pop out and stay out for at least 2 minutes. If the needle and seat are leaking or in the wrong position the indicator will not stay out for more than a couple of seconds or at all.

 

[scottcab]

A New Diagnosis/Problem what do yall think

A New Diagnosis/Problem what do yall think

Okay all, the next saga begins.

The motor is the right height now. Thanks to all that contributed to that. The Jack plate worked perfect.

The fuel from the carb thing: No fuel doesn't come out of the (arrowed) tubes while the motor is off. I can pump up the primer bulb and it stays firm for a little while (1-2 min). The indicator on the back of the fuel pump (little gray nipple thing) comes out when primed and stays out for a long time. The question of the fuel coming from the tubes originates from my finding a decent amount of fuel inside the engine compartment after running. not sure of where it is coming from, but it seems to be coming out of the throat of the carbs or something. Not like flowing or running, but somehow splashing or something. I had the front of the air silencer box off.

Now to the spitting and spurtering then reving thing. I had her at the lake today and it seemed to spit and spurter after about 3 mins of running. I figured I would take the cowling off and attempt to locate where the fuel was coming from. I took the hood off and attempted to run the boat (remember the front of the air box was off too). The boat ran LIKE A BAT OUTTA HELL. It ran perfect, like a GD Race Boat or something. I was able to run at 5600rpm, yes 5600rpm and 43mph with that same 17pitched sst prop. No sputering or anything. Then I put the hood back on and we are back to sputerring skipping and bogging down. Back to 4100rpm and 33mph. My first thoughts were that buy allowing fresh air to enter the front of the carbs, I had created a hood scoop type effects creating the change by giving the motor more air and leaning out the fuel to the right fuel/air ratio. Then I figured I would check the forums

After finding this out I figured that maybe I needed to consult the experts. I went on iboats and found a forum of someone who was lossing power when the hood was on but running fine with it off. Someone suggested that it was a exhaust leak filling the hood and making the motor take dirty air in the intake.

Immediately, I started shaking my head. I remember seeing a exhaust leak from the bottom of the head area when buying the motor. Is it possible that this is the cause of my woes???

Please let me know what yall think. In an attempt to try to error trap the problem, I am about to head to the lake with the boat again. The test I will be running is trying to run the boat with the air box front on it and the cowling off. This will eliminate the forced air induction and allow the motor to run at the set fuel air ratio. If it is an exhaust leak, I would think that the motor should run just as good or almost just as good with the airbox lid on and the cowling off.

Thanks for your time and input. I REALLY appreciate all of you that have been so willing to donate your time and help me out.
Scott

 

[SparkieBoat]

Re: A New Diagnosis/Problem what do yall think

Re: A New Diagnosis/Problem what do yall think

your hood latch may be shorting out one of your coils or plug wires..those models are notorious for the latch catching a plug wire. also if someone put your coil(s) on inside out the latch will hit against the coil where the plug wire attaches. if you lose power after the hood it is most likely something like what I am talking about. if it runs great with hood off..then carbs are probably ok.

 

[scottcab]

ALL FIXED and running great!!! Thanks ALL

ALL FIXED and running great!!! Thanks ALL

Sparkie, you couldn't be anymore right!

After running it on test with the air box lid on and so forth I decided to put the hood back on as it was running. After the front latch no issues. Same after the back left, but when I went to move the back right latch the motor started the b.s. skipping/sputerring lack of power thing. So I left the back right off. The motor ran awesome. I am getting all of the power that yall kept telling me that I should have been getting. Also, with the 17 pitch sst prop, now I am getting 5750rpm and 44mph. What a difference one latch can make

Sure am glad I waited for the 15 pitch prop :-D

I know that the service manual tells me that my WoT range should be 4500-5500. Obviously, I am good to go for now. But when the wife gets back to work and money isn't so tight, would a 19 or 20 pitch prop be a good idea for when I am alone. What do yall think that going to a 19 pitch stainless prop would do to my max speed? (just curious)

Thanks again to everyone that assisted in the setup of this boat/motor. I am incredibly grateful for yall sharing your knowledge to help me out. Without yall, I would still be dead on the trailer.

Scott

 

[SparkieBoat]

Re: ALL FIXED and running great!!! Thanks ALL

Re: ALL FIXED and running great!!! Thanks ALL

stay with the 17 prop...I like my motors to run around 5800 unloaded. congrats you may either need to flip your coil over or re route the plug wire.

 

[wired247]

Re: Outboard mounting height 1985 Johnson 115 v4

With a 19 pitch SST prop and a 140/115 on a 17 foot 1981 checkmate enticer I can hit 54 mph at 5800 RPM. With a 23 pitch SOLAS prop and no one else onboard I can hit 60 mph at 6000 rpm.

 

[scottcab]

More problems with the hood on

More problems with the hood on

Still have problems. Unfortunately, i took the boat out fishin for the first time today and ran into some problems. The motor ran like it was having the power restricted when the hood is on the motor even with the latch not latched. It doesnt appear that anything is shorting now. I switched the sprak plug cable that was getting hit by the latch. With the hood on the motor runs really restricted and doesnt even wanna plane off now. Once i take the hood off it runs like crap for about 10secs as if there is too much fuel in the carbs, then it takes off and runs like a champ. It still seems alittle rough at idle or just above idle even with the cowling off, but good at full throtle.


Please bring ideas
Thanks
Scott

 

[SparkieBoat]

Re: More problems with the hood on

Re: More problems with the hood on

take a pic of the coil on the side of the problem latch..

 

[scottcab]

Re: More problems with the hood on

Re: More problems with the hood on

take a pic of the coil on the side of the problem latch..

Here is the coils on the side that 'was' shorting out. Or so i think.

 

[bob johnson]

Re: Outboard mounting height 1985 Johnson 115 v4

I dont know why he wanted to see a picture of the cvoil...but it looks like there is corrosion under the bolts that contact the wires for grounding the coil....

there might be a cleaning needed there....

good luck

bob

 

[SparkieBoat]

Re: Outboard mounting height 1985 Johnson 115 v4

I wanted to see which way the coil prong was facing.. looks like that top coil has taken a beating, I also see some electrical tape on that one boot, crank it up at night and press around the coil and plug wires some and look for some arcing. what I have seen happen is the prong gets bumped and cracks next to the coil body and can cause arcing/loose connection when even the slightest pressure hits it. Try flipping your coils over so the prong is on the outside, see if that fixes your problem. I cannot remember which way I ended up turning mine to fix my problem. probably replace that top coil and wire. get a CDI coil, I have had great service out of them.